(1) Field of the Invention
The present invention relates to a lancing device for pricking skin with a tip end of a lancet to take blood or other body fluid or tissue for testing.
(2) Description of Related Art
FIG. 12 illustrates an example of conventional lancing device disclosed in Patent Document 1. In the lancing device B illustrated in the figure, a control member 230 including a control portion 230a, a lancet holder 220, an advance spring 280 and a return spring 270 are accommodated in a housing 210. When the control member 230 is retreated in the arrow Rr direction by handling the control portion 230a, the lancet holder 220 also retreats, compressing the advance spring 280. Thereafter, by using the resilient force of the advance spring 280, the lancet holder 220 quickly advances in the arrow Fr direction so that the needle 290a of the lancet 290 pricks a lancing target portion (not shown). In this way, the lancing target portion is caused to bleed, and blood can be taken from this portion for testing. The return spring 270 functions to return the control member 230 to its original wait position after the above-described operation is performed. Further, when the control member 230 is moved forward with the cap 240 of the housing 210 removed, the front end 233 of the control member 230 pushes the lancet 290 forward for detachment from the lancet holder 220. In this way, the lancet 290 after use is easily removed.
However, in the above-described lancing device B, after the control member 230 is advanced to detach the used lancet 290 from the lancet holder 220, the control member 230 does not automatically return to the original wait position. Thus, the user needs to operate the control portion 230a to return the control member 230 to the original wait position, which is troublesome. As a means to solve this problem, it may be considered to provide an additional return spring to retreat the control member 230 after it is advanced to detach the lancet 290 from the lancet holder 220. However, to employ this means leads to increase in number of parts, complicated structure, and increase in size of the lancing device and manufacturing cost.
Patent Document 1: JP-A-2000-262498